add Gitignore (#251)

lua/nvim-tree/populate.lua

@@ -100,6 +100,21 @@ end
 
 local function gen_ignore_check()
   local ignore_list = {}
+
+  local function add_toignore(path)
+    local content = utils.read_file(path)
+    for s in content:gmatch("[^\r\n]+") do
+      ignore_list[s] = true
+    end
+  end
+
+  if (vim.g.nvim_tree_gitignore or 0) > 0 then
+    add_toignore('.gitignore')
+  end
+  if (vim.g.nvim_tree_gitignore or 0) == 2 then
+    add_toignore(git.get_path_gitexclude())
+  end
+  
   if vim.g.nvim_tree_ignore and #vim.g.nvim_tree_ignore > 0 then
     for _, entry in pairs(vim.g.nvim_tree_ignore) do
       ignore_list[entry] = true